regex to find inner most occurrence of strings between two delimiters - regex

I am using TextCrawler *regxp* to align existing plain text file.
Text inside the file are continuous without line break.
....moredata....
,actor's list:
Amy Brenneman, Aaron Eckhart, Catherine Keener, Natassja Kinski
, Jason Patric, Ben Stiller,
movies released:
Gladiator,Matrix Reloaded,The Shawshank Redemption,Pirates of the Caribbean
- Curse of the Black Pearl,Monsters Inc,
genre:
SciFi,Romance,Drama,Action,Comedy,Advenure,Animated,Western,Horror
....moredata....
I am trying to find the string(s) between the comma and the colon and replace with the same but with new line added before found pattern.
I tried following, but it matching string form outermost comma to colon.
[,]{1}.[A-Z].*[:]
Any idea on the same ? Where i went wrong?

Why not use this pattern:
search: (?<=,)[^,:]+(?=:)
replace: \n$0
pattern details:
(?<=,) # lookbehind assertion: only a check that means "preceded by ,"
[^,:]+ # negated char class: all characters except , and :
(?=:) # lookahead assertion: only a check that means "followed by :"
Lookarounds are only tests that can make the pattern fail or succeed, they are not part of the match result.

The below mentioned pattern works:
Search Pattern : (,?[^:,]+:)
Replacement String : \n\1\n
For eg:
Given a file a.txt with contents :
actor's list:A,B,C,movies released:D,E,F,genre:G,H,I
perl -pe "s#(,?[^:,]+:)#\n\1\n#g" a.txt
The above command produces a output of the below format :
actor's list:
A,B,C
,movies released:
D,E,F
,genre:
G,H,I
I hope the the above output is what you are expecting.

Related

Regex for text (and numbers and special characters) between multiple commas [duplicate]

I'm going nuts trying to get a regex to detect spam of keywords in the user inputs. Usually there is some normal text at the start and the keyword spam at the end, separated by commas or other chars.
What I need is a regex to count the number of keywords to flag the text for a human to check it.
The text is usually like this:
[random text, with commas, dots and all]
keyword1, keyword2, keyword3, keyword4, keyword5,
Keyword6, keyword7, keyword8...
I've tried several regex to count the matches:
-This only gets one out of two keywords
[,-](\w|\s)+[,-]
-This also matches the random text
(?:([^,-]*)(?:[^,-]|$))
Can anyone tell me a regex to do this? Or should I take a different approach?
Thanks!
Pr your answer to my question, here is a regexp to match a string that occurs between two commas.
(?<=,)[^,]+(?=,)
This regexp does not match, and hence do not consume, the delimiting commas.
This regexp would match " and hence do not consume" in the previous sentence.
The fact that your regexp matched and consumed the commas was the reason why your attempted regexp only matched every other candidate.
Also if the whole input is a single string you will want to prevent linebreaks. In that case you will want to use;
(?<=,)[^,\n]+(?=,)
http://www.phpliveregex.com/p/1DJ
As others have said this is potentially a very tricky thing to do... It suffers from all of the same failures as general "word filtering" (e.g. people will "mask" the input). It is made even more difficult without plenty of example posts to test against...
Solution
Anyway, assuming that keywords will be on separate lines to the rest of the input and separated by commas you can match the lines with keywords in like:
Regex
#(?:^)((?:(?:[\w\.]+)(?:, ?|$))+)#m
Input
Taken from your question above:
[random text, with commas, dots and all]
keyword1, keyword2, keyword3, keyword4, keyword5,
Keyword6, keyword7, keyword8
Output
// preg_match_all('#(?:^)((?:(?:[\w]+)(?:, ?|$))+)#m', $string, $matches);
// var_dump($matches);
array(2) {
[0]=>
array(2) {
[0]=>
string(49) "keyword1, keyword2, keyword3, keyword4, keyword5,"
[1]=>
string(31) "Keyword6, keyword7, keyword8..."
}
[1]=>
array(2) {
[0]=>
string(49) "keyword1, keyword2, keyword3, keyword4, keyword5,"
[1]=>
string(31) "Keyword6, keyword7, keyword8"
}
}
Explanation
#(?:^)((?:(?:[\w]+)(?:, ?|$))+)#m
# => Starting delimiter
(?:^) => Matches start of line in a non-capturing group (you could just use ^ I was using |\n originally and didn't update)
( => Start a capturing group
(?: => Start a non-capturing group
(?:[\w]+) => A non-capturing group to match one or more word characters a-zA-Z0-9_ (Using a character class so that you can add to it if you need to....)
(?:, ?|$) => A non-capturing group to match either a comma (with an optional space) or the end of the string/line
)+ => End the non-capturing group (4) and repeat 5/6 to find multiple matches in the line
) => Close the capture group 3
# => Ending delimiter
m => Multi-line modifier
Follow up from number 2:
#^((?:(?:[\w]+)(?:, ?|$))+)#m
Counting keywords
Having now returned an array of lines only containing key words you can count the number of commas and thus get the number of keywords
$key_words = implode(', ', $matches[1]); // Join lines returned by preg_match_all
echo substr_count($key_words, ','); // 8
N.B. In most circumstances this will return NUMBER_OF_KEY_WORDS - 1 (i.e. in your case 7); it returns 8 because you have a comma at the end of your first line of key words.
Links
http://php.net/manual/en/reference.pcre.pattern.modifiers.php
http://www.regular-expressions.info/
http://php.net/substr_count
Why not just use explode and trim?
$keywords = array_map ('trim', explode (',', $keywordstring));
Then do a count() on $keywords.
If you think keywords with spaces in are spam, then you can iterate of the $keywords array and look for any that contain whitespace. There might be legitimate reasons for having spaces in a keyword though. If you're talking about superheroes on your system, for example, someone might enter The Tick or Iron Man as a keyword
I don't think counting keywords and looking for spaces in keywords are really very good strategies for detecting spam though. You might want to look into other bot protection strategies instead, or even use manual moderation.
How to match on the String of text between the commas?
This SO Post was marked as a duplicate to my posted question however since it is NOT a duplicate and there were no answers in THIS SO Post that answered my question on how to also match on the strings between the commas see below on how to take this a step further.
How to Match on single digit values in a CSV String
For example if the task is to search the string within the commas for a single 7, 8 or a single 9 but not match on combinations such as 17 or 77 or 78 but only the single 7s, 8s, or 9s see below...
The answer is to Use look arounds and place your search pattern within the look arounds:
(?<=^|,)[789](?=,|$)
See live demo.
The above Pattern is more concise however I've pasted below the Two Patterns provided as solutions to THIS this question of matching on Strings within the commas and they are:
(?<=^|,)[789](?=,|$) Provided by #Bohemian and chosen as the Correct Answer
(?:(?<=^)|(?<=,))[789](?:(?=,)|(?=$)) Provided in comments by #Ouroborus
Demo: https://regex101.com/r/fd5GnD/1
Your first regexp doesn't need a preceding comma
[\w\s]+[,-]
A regex that will match strings between two commas or start or end of string is
(?<=,|^)[^,]*(?=,|$)
Or, a bit more efficient:
(?<![^,])[^,]*(?![^,])
See the regex demo #1 and demo #2.
Details:
(?<=,|^) / (?<![^,]) - start of string or a position immediately preceded with a comma
[^,]* - zero or more chars other than a comma
(?=,|$) / (?![^,]) - end of string or a position immediately followed with a comma
If people still search for this in 2021
([^,\n])+
Match anything except new line and comma
regexr.com/60eme
I think the difficulty is that the random text can also contain commas.
If the keywords are all on one line and it is the last line of the text as a whole, trim the whole text removing new line characters from the end. Then take the text from the last new line character to the end. This should be your string containing the keywords. Once you have this part singled out, you can explode the string on comma and count the parts.
<?php
$string = " some gibberish, some more gibberish, and random text
keyword1, keyword2, keyword3
";
$lastEOL = strrpos(trim($string), PHP_EOL);
$keywordLine = substr($string, $lastEOL);
$keywords = explode(',', $keywordLine);
echo "Number of keywords: " . count($keywords);
I know it is not a regex, but I hope it helps nevertheless.
The only way to find a solution, is to find something that separates the random text and the keywords that is not present in the keywords. If a new line is present in the keywords, you can not use it. But are 2 consecutive new lines? Or any other characters.
$string = " some gibberish, some more gibberish, and random text
keyword1, keyword2, keyword3,
keyword4, keyword5, keyword6,
keyword7, keyword8, keyword9
";
$lastEOL = strrpos(trim($string), PHP_EOL . PHP_EOL); // 2 end of lines after random text
$keywordLine = substr($string, $lastEOL);
$keywords = explode(',', $keywordLine);
echo "Number of keywords: " . count($keywords);
(edit: added example for more new lines - long shot)

How can I search and replace guids in Sublime 3

I have a textfile where I would like to replace all GUIDs with space.
I want:
92094, "970d6c9e-c199-40e3-80ea-14daf1141904"
91995, "970d6c9e-c199-40e3-80ea-14daf1141904"
87445, "f17e66ef-b1df-4270-8285-b3c15da366f7"
87298, "f17e66ef-b1df-4270-8285-b3c15da366f7"
96713, "3c28e493-015b-4b48-957f-fe3e7acc8412"
96759, "3c28e493-015b-4b48-957f-fe3e7acc8412"
94665, "87ac12a3-62ed-4e1d-a1a6-51ae05e01b1a"
94405, "87ac12a3-62ed-4e1d-a1a6-51ae05e01b1a"
To become:
92094,
91995,
87445,
87298,
96713,
96759,
94665,
94405,
How can i accomplish this in Sublime 3?
Ctrl+H
Find: "[\da-f-]{36}"
Replace: LEAVE EMPTY
Enable regex mode
Replace all
Explanation:
" : double quote
[ : start class character
\d : any digit
a-f : or letter from a to f
- : or a dash
]{36} : end class, 36 characters must be present
" : double quote
Result for given example:
92094,
91995,
87445,
87298,
96713,
96759,
94665,
94405,
Try doing a search for this pattern in regex search mode:
"[0-9a-z]{8}-[0-9a-z]{4}-[0-9a-z]{4}-[0-9a-z]{4}-[0-9a-z]{12}"
And then just replace with empty string. This should strip off the GUID, leaving you with the output you want.
Demo
Another regex solution involving a slightly different search-replace strategy where we don't care about the GUI format and simply get the first column:
Search for ([^,]*,).* (again don't forget to activate the regex mode .*).
Replace with $1.
Details about the regular expression
The idea here is to capture all first columns. A column here is defined by a sequence of
"some non-comma character": [^,]*
followed by a comma: [^,]*,
The first column can then be followed by anything .* (the GUI format doesn't matter): [^,]*,.*
Finally we need to capture the 1st column using group capturing: ([^,]*,).*
In the replace field we use a backreference $x which refers the the x-th capturing group.

Regex Lookahead/Lookbehind if more than one occurance

I have string formulas like this:
?{a,b,c,d}
It can be can be embedded like this:
?{a,b,c,?{x,y,z}}
or this is the same:
?{a,b,c,
?{x,y,z}
}
So I have to find those commas, what are in the second and greather "level" brackets.
In the example below I marked the "levels" where I have to find all commas:
?{a,b,c,
?{x,y, <--Those
?{1,2,3} <--Those
}
}
I've tried with lookahead and lookbehind, but I'm totally confused now :/
Here is my latest working try, but it is not good at all:
OnlineRegex
Update:
To avoid misunderstanding, I don't want to count the commas.
I'd like to get groups of commas to replace them.
The condition is find the commas where more than one "open tags" before it like this: ?{
.. without closing tag like this: }
Examlpe.:
In this case I have not replace any commas:
?{1,2,3} ?{a,b,c}
But in this case I have to replace commas between a b c
?{1,2,3,?{a,b,c}}
For the examples which you have provided, the following regex works(gives the desired output as mentioned by you):
(?<!^\?{[^{}]*),(?=[\s\S]*(?:\s*}){2,})
For String ?{a,b,c,d}, see Demo1 No Match
For String, ?{a,b,c,?{x,y,z}}, see Demo2 Match successful
For String,
?{a,b,c,
?{x,y,z}
}
see Demo3 Match Successful
For String,
?{a,b,c,
?{x,y,
?{1,2,3}
}
}
see Demo4 Match Successful
For String ?{1,2,3} ?{a,b,c} ?{1,2,3} ?{a,b,c}, see Demo5 No Match
Explanation:
(?<!^\?{[^{}]*), - negative lookbehind to discard the 1st level commas. The logic applied here is it should not match the comma which is preceded by start of the string followed by ?{ followed by 0+ occurrences of any character except { or }
(?=[\s\S]*(?:\s*}){2,}) - The comma matched above must be followed by atleast 2 occurrences of }(consecutive or having only whitespaces between them)
Your question is rather unclear #norbre, but I presume you'd like to extract (i.e. "count") the number of commas.
You can't do this with a regex. Regexps can't count number of occurences. However, you can use this to extract the "internal part" and then use a spreadsheet formula to count number of commas:
^(?:\?{[a-zA-Z0-9,]+?,\n??\s*?\?{)([a-zA-Z0-9,?{}\n\s]+?(?:\n*?\s*?|})+)(?:[a-zA-Z0-9,\n\s]*})$
Try: https://regex101.com/r/Rr0eFo/5
Examples
1.
Input:
?{a,b,c,?{e,f},1,2,3}
Output:
e,f}
2.
Input:
?{a,b,c,
?{x,y,z,e,
?{1,2,3,?{f,g,3},4,5,6}
}
,d,e,f}
Output:
x,y,z,e,
?{1,2,3,?{f,g,3},4,5,6}
}
3.
Input:
?{a,b,c,?{e},1,2,3}
Output:
e}
(note that there are no commas here!)
One caveat however. As I have said, regexps can't count number of occurences.
Hence, the following sample (don't know if it's valid or not for your case) would return wrong match:
?{a,b,c,?{e,f}
,1,2,3,?{a,b}
}
Output:
e,f}
,1,2,3,?{a,b}
OK replacing commas is another story so I'll add another answer.
Your regexp engine would need to support recursion.
Still I don't see a way to do it with one regex - one match would either contain the first comma or contain everything between the braces!
What I suggest is to use one regexp to get "what is inside the inner braces", run a replace (, => "") and assemble the whole line again using submatches from the regexp.
Here it is: (\?{[^?{}]*)((?>[^?{}]|(?R))+?)([^?{}]*?\})
Try: https://regex101.com/r/IzTeY0/3
Example 1:
Input:
?{a,b,c,
?{x,y,z,e,
?{1,2,3,?{f,g,3},4,5,6}
}
,d,e,f}
Submatches:
1. ?{a,b,c,
2. ?{x,y,z,e,
?{1,2,3,?{f,g,3},4,5,6}
}
3.
,d,e,f}
Replace all commas in submatch 2 with anything you want, then reassamble the whole string using submatches 1 and 3.
Again, this would break the regexp:
?{a,b,c,?{e,f}
,1,2,3,?{a,b}
}
Submatch 2 would look like this:
?{e,f}
,1,2,3,?{a,b}

Regular Expression: Extract the lines

I try to extract the name1 (first-row), name2 (second-row), name3 (third-row) and the street-name (last-row) with regex:
Company Inc.
JohnDoe
Foobar
Industrieterrein 13
The very last row is the street name and this part is already working (the text is stored in the variable "S2").
REGEXREPLACE(S2, "(.*\n)+(?!(.*\n))", "")
This expression will return me the very last line. I am also able the extract the first row:
REGEXREPLACE(S2, "(\n.*)", "")
My problem is, that I do not know how to extract the second and third row....
Also how do I test if the text contains one, two, three or more rows?
Update:
The regex is used in the context of Scribe (a ETL tool). The problem is I can not execute sourcecode, I only have the following functions:
REGEXMATCH(input, pattern)
REGEXREPLACE(input, pattern, replacement)
If the regex language provides support for lookaheads you may count rows backwards and thus get (assuming . does not match newline)
(.*)$ # matching the last line
(.*)(?=(\n.*){1}$) # matching the second last line (excl. newline)
(.*)(?=(\n.*){2}$) # matching the third last line (excl. newline)
just use this regex:
(.+)+
explain:
.
Wildcard: Matches any single character except \n.
+
Matches the previous element one or more times.
As for a regular expression that will match each of four rows, how about this:
(.*?)\n(.*?)\n(.*?)\n(.*)
The parentheses will match, and the \n will match a new line. Note: you may have to use \r\n instead of just \n depending; try both.
You can try the following:
((.*?)\n){3}

Replace patterns that are inside delimiters using a regular expression call

I need to clip out all the occurances of the pattern '--' that are inside single quotes in long string (leaving intact the ones that are outside single quotes).
Is there a RegEx way of doing this?
(using it with an iterator from the language is OK).
For example, starting with
"xxxx rt / $ 'dfdf--fggh-dfgdfg' ghgh- dddd -- 'dfdf' ghh-g '--ggh--' vcbcvb"
I should end up with:
"xxxx rt / $ 'dfdffggh-dfgdfg' ghgh- dddd -- 'dfdf' ghh-g 'ggh' vcbcvb"
So I am looking for a regex that could be run from the following languages as shown:
+-------------+------------------------------------------+
| Language | RegEx |
+-------------+------------------------------------------+
| JavaScript | input.replace(/someregex/g, "") |
| PHP | preg_replace('/someregex/', "", input) |
| Python | re.sub(r'someregex', "", input) |
| Ruby | input.gsub(/someregex/, "") |
+-------------+------------------------------------------+
I found another way to do this from an answer by Greg Hewgill at Qn138522
It is based on using this regex (adapted to contain the pattern I was looking for):
--(?=[^\']*'([^']|'[^']*')*$)
Greg explains:
"What this does is use the non-capturing match (?=...) to check that the character x is within a quoted string. It looks for some nonquote characters up to the next quote, then looks for a sequence of either single characters or quoted groups of characters, until the end of the string. This relies on your assumption that the quotes are always balanced. This is also not very efficient."
The usage examples would be :
JavaScript: input.replace(/--(?=[^']*'([^']|'[^']*')*$)/g, "")
PHP: preg_replace('/--(?=[^\']*'([^']|'[^']*')*$)/', "", input)
Python: re.sub(r'--(?=[^\']*'([^']|'[^']*')*$)', "", input)
Ruby: input.gsub(/--(?=[^\']*'([^']|'[^']*')*$)/, "")
I have tested this for Ruby and it provides the desired result.
This cannot be done with regular expressions, because you need to maintain state on whether you're inside single quotes or outside, and regex is inherently stateless. (Also, as far as I understand, single quotes can be escaped without terminating the "inside" region).
Your best bet is to iterate through the string character by character, keeping a boolean flag on whether or not you're inside a quoted region - and remove the --'s that way.
If bending the rules a little is allowed, this could work:
import re
p = re.compile(r"((?:^[^']*')?[^']*?(?:'[^']*'[^']*?)*?)(-{2,})")
txt = "xxxx rt / $ 'dfdf--fggh-dfgdfg' ghgh- dddd -- 'dfdf' ghh-g '--ggh--' vcbcvb"
print re.sub(p, r'\1-', txt)
Output:
xxxx rt / $ 'dfdf-fggh-dfgdfg' ghgh- dddd -- 'dfdf' ghh-g '-ggh-' vcbcvb
The regex:
( # Group 1
(?:^[^']*')? # Start of string, up till the first single quote
[^']*? # Inside the single quotes, as few characters as possible
(?:
'[^']*' # No double dashes inside theses single quotes, jump to the next.
[^']*?
)*? # as few as possible
)
(-{2,}) # The dashes themselves (Group 2)
If there where different delimiters for start and end, you could use something like this:
-{2,}(?=[^'`]*`)
Edit: I realized that if the string does not contain any quotes, it will match all double dashes in the string. One way of fixing it would be to change
(?:^[^']*')?
in the beginning to
(?:^[^']*'|(?!^))
Updated regex:
((?:^[^']*'|(?!^))[^']*?(?:'[^']*'[^']*?)*?)(-{2,})
Hm. There might be a way in Python if there are no quoted apostrophes, given that there is the (?(id/name)yes-pattern|no-pattern) construct in regular expressions, but it goes way over my head currently.
Does this help?
def remove_double_dashes_in_apostrophes(text):
return "'".join(
part.replace("--", "") if (ix&1) else part
for ix, part in enumerate(text.split("'")))
Seems to work for me. What it does, is split the input text to parts on apostrophes, and replace the "--" only when the part is odd-numbered (i.e. there has been an odd number of apostrophes before the part). Note about "odd numbered": part numbering starts from zero!
You can use the following sed script, I believe:
:again
s/'\(.*\)--\(.*\)'/'\1\2'/g
t again
Store that in a file (rmdashdash.sed) and do whatever exec magic in your scripting language allows you to do the following shell equivalent:
sed -f rmdotdot.sed < file containing your input data
What the script does is:
:again <-- just a label
s/'\(.*\)--\(.*\)'/'\1\2'/g
substitute, for the pattern ' followed by anything followed by -- followed by anything followed by ', just the two anythings within quotes.
t again <-- feed the resulting string back into sed again.
Note that this script will convert '----' into '', since it is a sequence of two --'s within quotes. However, '---' will be converted into '-'.
Ain't no school like old school.